Management of heterogeneous field devices, i.e. devices made by different manufacturers, initially was realized by embedding software of a main controller into multiple hardware devices connected to the main controller. However, it is difficult to embed software into various manufacturers' hardware devices. Subsequently, multiple hardware devices are virtual software-defined in a centralized way in an industrial server, and control of the multiple hardware devices are realized through virtual software.
The soft programmable logic controller (PLC), soft computer numerical control (CNC) and soft numerical control (NC), being cost-effective, are able to take advantage of various operating environments, and to be widely applied in the industrial control field.
At present, there are two solutions of integrating the functions of a soft PLC, a soft CNC or a soft NC into an industrial system.
One solution is to integrate the functions of a soft PLC, a soft NC or a soft CNC into a main stream operating system (such as windows) as an application program, whose operating environment is a process state in the operating system.
The other solution is to integrate the functions of a soft PLC, a soft NC or a soft CNC into a main stream operating system (such as windows) as a system service, whose operating environment is a process state with high scheduling priority in the operating system.
However, these two solutions don't solve the problems of the lack of isolation, security and reliability of various services (mainly management services and industrial field control services) of a soft PLC, a soft NC or a soft CNC, and don't meet certain industrial requirements which require high isolation, security and reliability of services. For example, when a system is supposed to be upgraded, or, a misoperation or a malicious virus attack occurs, it would cause all the services to be interrupted or run abnormally. Moreover, hackers are familiar with main stream operating systems such as windows, and thus main stream operating systems are vulnerable to hackers' attacks.